The following code example demonstrates the use of the ReportProgress method to report the progress of an asynchronous operation to the user. This code example is part of a larger example provided for the BackgroundWorker class.

// Abort the operation if the user has cancelled. // Note that a call to CancelAsync may have set // CancellationPending to true just after the // last invocation of this method exits, so this // code will not have the opportunity to set the // DoWorkEventArgs.Cancel flag to true. This means // that RunWorkerCompletedEventArgs.Cancelled will // not be set to true in your RunWorkerCompleted // event handler. This is a race condition. if ( worker->CancellationPending )
{
e->Cancel = true;
}
else
{
if ( n < 2 )
{
result = 1;
}
else
{
result = ComputeFibonacci( n - 1, worker, e ) + ComputeFibonacci( n - 2, worker, e );
}
// Report progress as a percentage of the total task. int percentComplete = (int)((float)n / (float)numberToCompute * 100);
if ( percentComplete > highestPercentageReached )
{
highestPercentageReached = percentComplete;
worker->ReportProgress( percentComplete );
}
}